(13-x)+(9-x)等于?

问题描述:

(13-x)+(9-x)等于?

(13-x)+(9-x)
=13-x+9-x
=(13+9)+(-x-x)
=22+(-2x)
=22-2x

(13-x)+(9-x)
=13-x+9-x
=22-2x

(13-x)+(9-x)=(13+9)+(-x-x)=22-2x

(13-x)+(9-x)
=13-x+9-x
=(13+9)-2x
=22-2x